For a navigation system, such as an in-car system, speech provides a natural modality of interaction. Speech, however, is constrained by the limitation of the language. For example, if a user wants to find restaurants or other points of interest (POIs) in a specific geographical area or a specific segment of a street, it is difficult for the user to describe the specific geographical area with language.
The limitations of speech have been addressed in some systems which incorporate a touch screen. In some of these systems, a user can “draw” a circle around a specific geographic location on the map using “gestures”. The drawing is made in a layer located above the depicted map. The system then applies the drawn geometric shape to the underlying map to specifically identify the geographic area of interest. Some of these systems can identify user gestures in the form of shapes, lines, and points. Thus, a user can use a circle-shaped gesture to identify a particular geographic region, or a line-shaped gesture to identify a street. In some known systems, once a specific geographic area is identified using gestures, various information about particular POIs within the specific geographic area may be extracted and communicated to the user.
While beneficial in many respects, known systems have various limitations. By way of example, while some systems include a form of error correction wherein a geographic shape is identified from one or more gestures which form an imperfect geometric shape, a user must still substantially complete the shape and then wait to see if the system correctly identifies the shape. The need to substantially complete drawing of the shape and then waiting to see if the system has correctly identified the shape results in undesired complication and delay. Such complications and delay can be distracting, particularly in situations where a driver of a vehicle is attempting to form the shape.
What is needed is a navigation system which intuitively identifies a geographic shape using partial gestures. A navigation system which predicts geographic areas based on user gesture data and conforms the predicted gesture data to a user-intended geographical feature of the map would be beneficial.